Field of the Invention
The present invention relates to a semiconductor package structure, and in particular to a highly cost-effective fan-out flip-chip package structure.
Description of the Related Art
In the semiconductor packaging industry, there is a desire for reducing the cost of packaging semiconductor dies. To accomplish this, a wide variety of package structure designs have been developed. One of the package structure designs currently in use is the flip-chip package structure.
In a flip-chip package structure, a semiconductor die (also referred to as an integrated circuit (IC) chip or “chip”) that is formed with solder bumps is typically bonded directly to metal pads of a package substrate. Such solder bumps are affixed to I/O bonding pads of the semiconductor die. During packaging, the semiconductor die is “flipped” so that the solder bumps form electrical interconnections between the semiconductor die and the packaging substrate. Flip chip package technology provides higher speed electrical performance than earlier wire bond technology, since this greatly shortens the interconnection path between the semiconductor die and the package substrate.
In order to ensure miniaturization and multi-functionality of electronic products, it is desired that semiconductor packages are small in size, operate at high speeds, and have high functionality. Accordingly, the semiconductor die needs to have more I/O pads put into a smaller area, and utilizes the package substrate to serve as a fan-out layer.
However, in order to respond to the increase in I/O pads, a complicated multilayer interconnect structure is formed in the package substrate. As a result, the dimensions and the manufacturing cost of the package substrate are greatly increased, while the yield of the package substrate is reduced. These cause reductions in the reliability, yield, and throughput of the semiconductor package structure, while the manufacturing cost of the semiconductor package structure goes up.
Thus, a novel semiconductor package structure is desirable.